Calutron receiver



Sept. 29, 1959 w. o. BRUNK CALUTRON RECEIVER 2 Sheets-Sheet 1 Filed Jan. 30, 1950 W/lys O. Bra/7k ATTaeA/sy Sept. 29, 1959 W. O. BRUNK CALUTRON RECEIVER Filed Jan. 30, 1950 2 Sheets-Sheet 2 INVENTOR. O. Brunk 4T TOENEV United States Patent() CALUTRON RECEIVER Willys 0. Brunk, Berkeley, Calif., assignor, by mesne assignments, to the United States of America as represented by the United States Atomic Energy Commission Application January 30, 1950, Serial No. 141,219

4 Claims. (Cl. Z50-41.9)

The present invention relates generally to isotope separating appartus of the electromagnetic type, commonly referred to as a calutron, and more particualrly to an improvement in the receiving unit for more efiiciently collecting the different isotopes after Athey have been separated into distinct ion beams in such apparatus. The invention is particularly concerned with the collection of the separated isotopes with a reduced amount of contamination than has previously been possible.

The invention is not limited to the separation of the isotopes of any particular element but may be employed in the separation of isotopes of any of various elements, the separation of isotopes of many different elements having already been successfully accomplished.

In a calutron, as is now well known, a beam of positive ions of the element to be separated is formed and projected at a uniform velocity into an evacuated region traversed by a substantially uniform magnetic field, the `ions being projected at right angles to the direction of the iield. As a result, each particular ion is caused to .describe a circular path having a radius proportional to the square root of its mass. single ion beam is divided into two or more fairly discrete component beams, each of which consists primarily of individual isotopes of the material. Because of a geometrical and magnetic focusing action, the various beams are most distinctly resolved after the completion of 180 degrees of their circular path; the various isotopes, that is, the beams, diverge from each other dependently on their separate masses, and the beams may be individually collected in a receiver located at the focal point.

AIt is desired, of course, that the collected isotopes be as free as possible from contamination by adjacent beams or foreign material and it has long been an objective in the art to contrive a receiver capable of achieving increased production without increased contamination. This objective, however, has been extremely difficult of attainment prior to the present invention. Receivers, as buil-t in the past, have customarily employed a face plate positioned at a substantial angle to the direction of the incoming ion beams with slots formed therein to receive the individual beams. In the past, the actual plane of the opening receiving the particularly desired isotope has coincided with the plane of the face plate of the receiver. In the present invention, the plane of this opening is substantially perpendicular as respects the entering ion beams. In this way, the actual opening through which the more desired isotope can be received is widened, while at the same time, the actual area of the opening through which foreign material, contamination, and scattered material may enter is reduced.

In this way, the original rrice Another object of the invention is to provide a calutron receiver having a face plate lying at an angle to the direction of the entering ion beams but having an opening the plane of which is in a substantially perpendicular plane as respects the entering ion beams.

Further objects and numerous advantages of the invention will become apparent from the following detailed description and annexed drawings, wherein:

Fig. l is a diagrammatic view partly in section showing isotope separating apparatus embodying the receiver of the invention.

Fig. 2 is a cross sectional View of the receiver of the present invention. Y

Fig. 3 is a front view partially broken away of the structure of Fig. 2.

Fig. 4 is a fragmentary detailed view showing the arrangement ofthe prior art which has been improved upon.

Referring to Fig. 1 of the drawings, there is shown an electromagnetic type isotope separating apparatus comprising a closed vessel 10 positioned in a substantially uniform transverse magnetic lield provided by a magnet, one pole piece 11 of which is'shown. The vessel 10 provides a space within which electromagnetic separation of ions may take place and is highly evacuated, although the presence of a small amount of gas is desirable under some circumstances to avoid so called space charge effects.

Within the closed vessel 10 and also within the region of influence of the magnetic lield, there is provided a source 12 of positive ions of an element, the isotopes of which it is desired to separate. An accelerating electrode 13 projects the ions emitted by source 12 in a direction normal to the magnetic iield and in the form of a discrete stream or beam A of ions having a uniform velocity. The accelerating electrode 13 is made negative with respect to the ion source 12 from any suitable direct current supply 14 which is preferably adjustable.

As is known, the ion beam A projected by the accelerating electrode 13 will follow a substantially circular orbit, as indicated, and after degrees of travel, the different isotopes will attain maximum separation. It is at this point that the receiver unit is positioned with its entrance slots coinciding as nearly as possible with the best foci of the isotope beams. As shown, there are two entrance slots, adapted to separately collect the isotopes identified as B and C, respectively. Ordinarily it is desired to collect and retain one of the isotopes in particular, and it will be herein assumed the B isotope-is such' isotope. B and C might, for example, represent Fe'-54 and Fe-56, respectively, or Cu-63 and Cu-65, respectively.

As will be described in detail in connection with Figs. 2 and 3, the receiver 1S has two separate pockets 16 and 17 and auxiliary electrode 18 all of which are electrically isolated and connected through meters 19, 20, and 21, respectively, so that the magnitude of their respective deionizing currents may be known for control and other purposes. ned in part by face plates 22 and 23, as will be described.

Referring now to Figs. 2 and 3, the receiver unit is shown in greater detail and as shown embodies the construction of the invention whereby more of the particularly desired beam, that is the beam of B ions, may be collected with less contamination than heretofore. As will be seen in Fig. 2, the face plate member 2S forms a partition between the pockets 16 and 17, and the line extending upwardly from the top edge of this member, identified as 0 angle, denes the dividing line between ions approaching at positive angles and negative angles. It will be noted that the lower edge of the defining plate 23 terminates on a plane perpendicular to the 0 angle identiiied as the M-E plane, so that the actual opening The entrance slots to the receiver 15 are de-` into pocket 16 lies in a plane. perpendicular to the direction of the incoming ion beam. Thus, any contaminating or scattering material, or other foreign material moving generally transversely to the vertical angle line sees no opening into pocketl. Fig. 4 shows the conventional structure of the prior art, showing the shape of the face plate member 23a which does not have the depending or extending edge and which results in the opening into the pocket 16a lying in a 45 degree plane, rather than in the M--E plane. The lower extending edge of plate 23 may take the form of a depending lip of material, resulting in the receiver being described as of the dip-lip type.

As observed, also in Fig. 2, the ions entering at positive angles actually see a wider opening with the arrangement shown in Fig. 2 than with the previous arrangement, as shown in Fig. 4. That is, the positive angle ions in Fig. 2 see an opening which is that lying in the M-E plane of Fig. 2.

The remaining construction of the receiver is conventional, the receiver itself being attached to a base as shown at 30. The face plate 31 overlies the defining plate 23, as shown, and is attached to the receiver by screws 32 and by end plates 33. The under side of the defining carbon 22 is waHedf as shown, to prevent peeling of long strips of deposited material which would cause electrical shorts between plate 22 and electrode 18.

The auxiliary electrode 18 is also waled on its under side, this electrode being for monitoring purposes through the meter 21. Pocket 16 is formed from member 25 and back plates 35 and 39, attached by screws as shown, and inside of this pocket is an additional wafed surface, as shown at 36. Pocket 16 is supported on insulators which are located immediately in back of plate 40. The pocket 17 is built up from plates 43, 44, 45, and 46, as shown, and it also has a waffled surface at 37.

From the foregoing, those skilled in the art will observe that I have provided a form of calutron receiver wherein the capabilities of the receiver to collect an individual isotope in its pure state are enhanced and the susceptibility of the device to permitting the entry of contaminating material is substantially reduced. The general construction of the apparatus as a whole may be varied considerably, of course, the invention lying primarily in the geometry, that is, the shape and positioning of the entrance slot into the receiver. The foregoing disclosure is primarily illustrative, and it is intended that the scope of the invention be determined in accordance with the claims appended hereto.

I claim:

1. A calutron receiver having at least one pocket adapted to receive an ion beam of particular isotopic content, face plate means forming a cover for said receiver and lying generally in a plane forming an acute angle with the incoming ion beam, said face plate means having an elongated slot therein for the entrance of ions into said pocket, said slot being formed by two facing surfaces comprising the two sides of said slot, the outer edge of one of said surfaces and the inner edge of the other of said surfaces both lying in a plane which is substantially normal to the incoming ion beam.

2. A calutron receiver having at least one pocket adapted to receive an ion beam of particular isotopic content, face plate means forming a cover for said receiver and lying generally in a plane forming an acute angle with the incoming ion beam, said face plate means having an elongated slot therein for the entrance of ions into said pocket, said slot being formed by two facing surfaces comprising the two sides of said slot, said surfaces converging toward each other in the direction of the incoming ion beam, the outer edge of one of said surfaces and the inner edge of the other of said surfaces lying in a plane which is substantially normal to the incoming ion beam.

3. A calutron receiver having at least one pocket adapted to receive an ion beam of particular isotopic content, face plate means forming a cover for said receiver and lying generally in a plane forming an acute angle with the incoming ion beam, said face plate means having an elongated slot therein for the entrance of ions into said pocket, said slot being formed by two facing surfaces comprising the two sides of said slot, the rst of said surfaces lying in a first plane which is parallel to the incoming ion beam, and the second of said surfaces lying in a second plane which intersects said first plane at an acute angle on the receiver side of said face plate means.

4. A calutron receiver having at least one pocket adapted to receive an ion beam of particular isotopic con.- tent, face plate means forming a cover for said receiver and lying generally in a plane forming an acute angle with the incoming ion beam, said face plate means having an elongated slot therein for the entrance of ions into said pocket, said slot being formed by two facing surfaces comprising the two sides of said slot, the flrst of said surfaces lying in a rst plane which is parallel to the incoming ion beam, and the second of said surfaces lying in a second plane which intersects said first plane at an acute angle on the receiver side of said face plate means, the outer edge of the first of said surfaces and the inner edge of the second of said surfaces both lying in a plane which is substantially normal to the incoming ion beam.

References Cited in the tile of this patent UNITED STATES PATENTS 2,427,484 West Sept. 16, 1947 

